As disclosed in U.S. Pat. No. 4,482,669 (Seyferth et al.-I), U.S. Pat. No. 4,645,807 (Seyferth et al.-II), U.S. Pat. No. 4,650,837 (Seyferth et al.-III), U.S. Pat. No. 4,835,207 (Semen et al.-I), U.S. Pat. No. 4,869,854 (Takeda et al.), and U.S. Pat. No. 4,895,889 (Semen et al.-II), it is known that polysilazanes can be used as binders for ceramic powders, such as silicon carbide and silicon nitride, to prepare molding compositions suitable for the production of ceramic articles. However, the known compositions have not proved to be entirely satisfactory for the production of articles by techniques requiring high flow, e.g., injection molding and extrusion processes.
The known polysilazanes can also be used to infiltrate fiber-reinforced ceramic composites and thus increase their density and strength, but their viscosities are higher and their ceramic yields lower than is desirable for an infiltrant.